William edward boyle



Jan. 3, 1928. 1,655,258

w. E. BOYLE HIGH TENSION CABLE AClNT Original Filed March 22, 1923INVENTOR L a M a; TTOR Y Patented Jan. 3, 1928.

UNITED STATES PATENT OFFICE.

WELIAM EDWARD BOYLE, OF NEW YORK,

N. Y., ASSIGNOB, BY MESNE ASSIGNMENTS,

TO ENGINEERING PRODUCTS CORPORATION, INC., 01: NEW YORK, N. Y., A CORPO-BATION 01: NEW YORK.

HIGH-TENSION-CABLE JOINT.

Continuation of application flerial llq, 626,758, tiled Harch'22, 1823.This annllcation nlcd May 28, 1824.

- Serial No. 715,314.

This invention relates I his application, is a. continuation of my"application Serial N umber 626,756, filed 5 March 22, 1923. The objectof the invention generally stated is a high tension cablejoint forunderground use which is capable of resisting to an unusual-degree theordinary break down and disruptive effects of electrical phenomenainhigh voltage transmiss on lines and particularly an improved method ofinsulation whereby an impaired cable may be economically joined andeifectivelyi' insulated 16 in the open air by an ordinary"'electricalworker to obtain a joint of a break down resistance equal to or greaterthan that of the original unimpaired cable. 1

1n the progress of the art the voltages ap- 20 plied to undergroundcables-are constantly being increased and it becomes increasinglydiflicult to obtain the-necessary higher dielectrie resistance withreasonable cost and within reasonable dimensions. The dielectricresistance must be'ell'cctive as against puncture or creepage in anydirection and involves the necessity of providing a joint as completelyfree as possible of entrapped air.

By my invention Lam enabled to produce a cheap, relatively small, jointcapable of withstanding very high voltages because it has not only ahigh dielectric resistance againstpuncture, or lateral resistance, butalso a very high dielectric resistance in any 5 possible creepage pathbetween contactin insulation parts from the conductor at the joint tothe cable sheath or to the metal enclosing the joint. My inventioninvolves a joint in which the bared ends of the conduc- 40 tors to bejoined are joined by a metal connector, preferably a sleeve; in whichthe bared ends of the conductor are covered by a tightly woundinsulating tape until'ga co'v ering is thus formed of the same diameteras 5 the usua mill insulation of the cable, this tape preferablycovering also previously g enciled ends of the mill insulation; vand in\rhicb'the core formed of the mill insulation -=nd the interveningtightly wound tape is so =.=irro,unded by rol'l f oiled pa or on thelike. The resulting 5 join is, o ne wh ch more thoroughly excludesz-lectrioresistance, both laterally and longilengt h is obtained,thecomparatively me- "chanically'nnperfect or soft ends of a reacontinuous tightly wound,

air thanany previous joint known to me and for this reason has a greatlyincreased dietudinally.

I have found, however, that by using a, slightly tapered sheet, it ispossible to wind such a roll of sheet insulation, even though roughlycut, around the joint by hand more tightly than is possible if a sheetof uniform width and smooth out is employed; and moreover that bywinding the wide end of the sheet first upon the joint a roll-of unusualtightness and-firmiiess throughout its versely wound roll or of a rollformed of a sheet of uniform width being obviated. 'lhe insulating rollmay be formed of a single continuous strip would tightly about itself,

but I'have found it preferable .in practice to divide the longer stripsinto longitudinally separated sections and" wind these sectionssuccessively upon each other to form the roll. For example if the totallength of strip and depth of roll'exceed certain limits, a roll ofgreater uniformity in tightness and hardness throughout its depth withgreater dielectric strength maythus be obtained.

For a. better understanding of this inventwo, reference may be had tothe following detailed description and the-accompanying drawings whereinY Fig. 1 is a longitudinal section through the cable joint;

Fig. 2 is a plan view of insulating strip employed in this invention;

Fig. 3 is a. view of the" strip rolled up;

Fig. 4 a view illustrating the winding of the strip about the joint;

Fig. 5 is a view of the strip wound about the joint and being tightenedand bound thereabout.

Referring to the drawings where like numerals designate similar partsthroughout, a cable is illustrated SFig. 1) having an interior conductor1, a aye-r or' covering of insulation 2 of suitable character and depth,and a metallic sheath 3 of the usual and standard ,chai'actei', thisbeing a cable or 'dinarily employed in underground high tensiontransmission lines. I ,l P

The cable is illustrated as 'haviii'gfi-li'eeii 'f broken or impaired in'the vicinity of point 4 and the present invention relates particularlyto the repairing of the insulation at this point and the building up ofthe insulation thereabo'ut of a character and in a manner to render theresistance of the cable to break down at this mintequal to or greaterthan that of the unimpaired parts of the insulated cable. The conductorparts 1 of the cable are mechanically and electrically connected andjoined together by means of a metallic sleeve 5 which surrounds andclosely e mbraces the free ends of the conductor 1 and is-seeured andsealed thereto in any suitable suit-able insulating material such aseambric tape," this 'tape beingjwound as indicated until the cable istilled in completely along the tapered lines 7 and the circumference ofthe insulation 8 forms an approxh'nate continuation of the circumferenceof the insula- -tion 2. A tapered strip of oiled insulating paper 9which is wide enough to bridgeand overla the taperedc'uds of theinsulation 2 iS'lllCIl wound and bound tightly about thein'sulation 8and the insulation'2 as a foundation, the strip being wound wide endfirst so as to form a built up insulation of cylindrical or roll form 10about the joint, the gradually narrowing of the tapered strip resultingin a slight sliorteningof the length of the r -ll from the inner surface11 to the miter surface 12. The drawings which are more or lessdiagrammatic show the buililin up of this tapered strip along thebevelor mnical edge- 13. After the insulat in; strip is wound --erytightlyabout the splice to torn: the cylindricalroll 10 it may besecured or ane-bored in posit-iouju 'any suitable manner t obviate anytendency of the roll to loosen. l have illustrated diagrammatically abinding means 14 disposed this operation a suitableinetalhc sheath orcontainer 1;? is positioned over the splice with its ends it; turnedover into engagc i ment with the metallicsheath 3, and sealed theretoto-enahlc' asuitalile tiller, such as petroleum -jellyor' otherinsulator, to be contained within the annular chamber formed thereby'ilioiit the splice," openings 17 are indicated for introducing thistiller. This filler serves the double purpose of insulating andexcluding air from about the s lice.

The strip 9 ma be of any suitablb and length, but have found a paperstrip 0.004 inches in thickness, approximately fift (50) '.-feet inlength, fourteen (14) inc es wide at the wide-end 18 and graduallynarrowing to a width-of twelve (12) inches at the narrower-end 19,suitable for a.cable of 5000. M. copper with 20/32" paper insulation,carryin a tension of 45,000V0lts delta or 26,000 volts to ground.

The strip 9 may be tapered in any suitable 'that the tapering isexaggerated in Fig. 2

to: o'onvemenoem illustration and exposiwidth tion. The strip thusformed is then wound y and bound tightly about'th'e s lice as in'-dicated in Figs. 4 and 5,. with t e wide end 18' wound ad acent to thefoundation of insulation 8 and covering .2. I have found it convenientto wind thestrip intq a roll illustrated in' Fig, 3 with the narrow endroll first and the wide end 18 outside as a preliminary step tobeginning the winding-of the samejaboutthe splice, Fig, 4 illustrat;-ing the beginning of thewindmg operation, although it is obvious thatthestrip ma be woundlabout the splicefas'indieated ig. 5 without thispreliminary rolling step. The drawings illustrate the referredprocedure'of bindihg'the joint with the tapered strip 9, when-done byhand, and such nand operation consists essentiall first winding th'estrip more'or less loose y aboutthe joint and then after'suchloose'winding without any particular efi'orts' to a tight wrapping, theroll is gripped'b' the hands as ndicat'cdin Fig, 5 -and t e roll boundtightly too by twisting the roll in the direction of wind 7 to tightenthe same, .each'suecessive superposed layer of turnt en'ding to bindtightly throughout its. width, against the next lower layer and preventtherebythe formation of air chambers at' any point therebetween throughwhich leakage. might take place with the resultant tendency todisruption and break downQ Thef roll of oiled paper about thecircuniference of insulation 10 at either end thereof" for this purpose.'After;

thus-,enel osing and binding the joint is noticeablysolid and firmthroughout its length, even at its ,ends.

Having thusZtlescribed invention what I claim desire to protect byLetters Iat- Tie tape directly surroundin the hated conrounding thecylindrical foundation and ductors, the connector and t e penciledporformed of an elongated sheet of insulation tions of the cableinsulation and built up to tightly wound about the foundation and a.diameter approximately that of the cable about itself. 5 insulation toform a substantially continu- In testimony whereof, I have signed my quscylindrical foundation therewith, and a name to this specification.closely wound roll of insulating material sur- WILLIAM EDWARD BOYLE.

